Home About us Contact
|
Home About us Contact | ||
|
|
||
Several New (several + new)
Terms modified by Several New Selected AbstractsReaction of 4,5,6-triaminopyrimidine and 2,4,5,6-tetraaminopyrimidine with 3-dimethylaminopropiophenones.JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 2 20003-dihydropyrimido[, 4]diazepines, 5- b][, Synthesis of new 4-aryl- Several new 6-amino- and 6,8-diamino-4-aryl-2,3-dihydropyrimido[4,5- b][1,4]diazepines were obtained from the reaction of 4,5,6-triaminopyrimidine 1a and 2,4,5,6-tetraaminopyrimidine 1b with one equivalent of 3-dimethylaminopropiophenones 2 in absolute ethanol. Structure analysis of 6-amino- and 6,8-diamino-4-aryl-2,3-dihydropyrimido[4,5- b][1,4]diazepines 3a-i, determined by detailed nmr measurements, reveals a high regioselectivity of this reaction. [source] Current and emerging concepts in tumour metastasis,THE JOURNAL OF PATHOLOGY, Issue 1 2010Caroline Coghlin Abstract Disseminated cancer accounts for most deaths due to malignancy. Despite this, research has focused predominantly on tumour development and progression at the primary site. Recently, attention has shifted towards the field of tumour metastasis. Several new and exciting concepts that have emerged in the past few years may shed light on this complex area. The established canonical theory of tumour metastasis, as a process emerging from a stepwise accumulation of genetic events fuelled by clonal evolution, has been challenged. New evidence suggests that malignant cells can disseminate at a much earlier stage than previously recognized in tumourigenesis. These findings have direct relevance to clinical practice and shed new light on tumour biology. Gene-profiling studies support this theory, suggesting that metastatic ability may be an innate property shared by the bulk of cells present early in a developing tumour mass. There is a growing recognition of the importance of host factors outside the primary site in the development of metastatic disease. The role of the ,pre-metastatic niche' is being defined and with this comes a new understanding of the function of bone marrow-derived progenitor cells in directing the dissemination of malignant cells to distant sites. Current research has highlighted the crucial roles played by non-neoplastic host cells within the tumour microenvironment in regulating metastasis. These new concepts have wide-ranging implications for our overall understanding of tumour metastasis and for the development of cancer therapeutics. Copyright © 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. [source] Synthesis and Cytotoxic Evaluation of 6-(3-Pyrazolylpropyl) Derivatives of 1,4-Naphthohydroquinone-1,4-diacetateARCHIV DER PHARMAZIE, Issue 10 2009Aurora Molinari Abstract Several new 6-(3-pyrazolylpropyl) derivatives of 1,4-naphthohydroquinone-1,4-diacetate (NHQ-DA) have been prepared by chemical modifications of the Diels,Alder adduct of ,-myrcene and 1,4-benzoquinone. All these new compounds and precursors have been evaluated in vitro for their cytotoxicity against cultured human cancer cells of MB-231 breast-adeno carcinoma, A-549 lung carcinoma, and HT-29 colon carcinoma. GI50 values ranged in and below the micromolar concentration level. [source] Twisted Intercalating Nucleic Acids , Intercalator Influence on Parallel Triplex StabilitiesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 17 2006Vyacheslav V. Filichev Abstract Phosphoramidites of several new twisted intercalating nucleic acid (TINA) monomers and the previously discovered (R)-1- O -[4-(1-pyrenylethynyl)phenylmethyl]glycerol (1) were synthesized and used in DNA synthesis. Stabilization of Hoogsteen-type triplexes was observed in cases of insertion of the novel (R)-1- O -[3-(naphthalen-1-ylethynyl)phenylmethyl]glycerol (2) as a bulge into homopyrimidine oligodeoxynucleotides (ONs), whereas phenylethynyl and 4-(biphenylylethynyl) derivatives of TINAs resulted in destabilization of parallel triplexes relative to the wild-type triplex. It was concluded that TINA monomers should possess at least two fused phenyl rings attached through the triple bond at the 4-position of bulged (R)-1- O -(phenylmethyl)glycerol in homopyrimidine ONs in order to stabilize parallel triplexes. Slight destabilization of DNA/DNA Watson,Crick type duplexes (,Tm = 1.0,4.5 °C) was detected for 2 inserted as a bulge, while RNA/DNA duplexes and duplexes with other TINA analogues were considerably destabilized (,Tm > 6.0 °C). In cases of double insertion of 1 opposite to base inversions in dsDNA, the thermal stabilities of the triplexes were higher than that of the wild-type triplex, which is a new solution to overcome the problem of targeting homopurine stretches with single base pair inversions. A DNA three-way junction was considerably stabilized (,Tm in a range of 10.0,15.5 °C) upon insertion of TINA monomers in the junction point as a bulge. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] Rho-GTPases: New members, new pathwaysJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 2 2005Elena M. Sorokina Abstract Proteins comprising the Rho family of GTPases mediate reorganization of the actin cytoskeleton as well as transcription of genes. Recent findings from genome sequencing efforts, genetic screens, and signal transduction research have revealed that the Rho family contains several new, hitherto unrecognized members. In this review, we focus on these newly discovered Rho-GTPases and discuss their role in signaling to the cytoskeleton and the nucleus. © 2004 Wiley-Liss, Inc. [source] Alcohol Biomarkers in Applied Settings: Recent Advances and Future Research OpportunitiesALCOHOLISM, Issue 6 2010Raye Z. Litten During the past decade, advances have been made in the identification, development, and application of alcohol biomarkers. This is important because of the unique functions that alcohol biomarkers can serve in various applied settings. To carry out these functions, biomarkers must display several features including validity, reliability, adequacy of temporal window of assessment, reasonable cost, and transportability. During the past two decades, several traditional alcohol biomarkers have been studied in multiple human studies. Meanwhile, several new, promising biomarkers, including various alcohol metabolites and alcohol biosensors, are being explored in human studies. In addition, researchers have explored using biomarkers in combination and using biomarkers in combination with self-reports, resulting in increased sensitivity with little sacrifice in specificity. Despite these advances, more research is needed to validate biomarkers, especially the new ones, in humans. Moreover, recent advances in high-throughput technologies for genomics, proteomics, and metabolomics offer unique opportunities to discover novel biomarkers, while additional research is needed to perfect newly developed alcohol sensors. Development of more accurate biomarkers will help practicing clinicians to more effectively screen and monitor individuals who suffer from alcohol use disorders. [source] Surface-enhanced Raman spectroscopy: advancements and applicationsJOURNAL OF RAMAN SPECTROSCOPY, Issue 6-7 2005Z. Q. Tian Abstract Since the mid-1990s, surface-enhanced Raman scattering (SERS) has advanced greatly and gained wider application and a renewal of interest. There have been several new and creative developments, e.g. SERS of single molecules, nanostructures and transition metals, tip-enhanced Raman scattering (TERS), surface-enhanced hyper-Raman scattering (SEHRS), ultraviolet-excited SERS (UV-SERS) and surface-enhanced resonance Raman scattering (SERRS), and their wide applications in biology, medicine, materials science and electrochemistry. It is timely to publish a special issue reporting these initiatives and the progress made in the past 7 years. This issue consists of 30 invited articles that are roughly divided into three SERS research themes: theories, methods and applications. These up-to-date representatives of the research results clearly show that SERS is important not only for Raman spectroscopy and surface science but also for nanoscience. Copyright © 2005 John Wiley & Sons, Ltd. [source] Photodynamic therapy: update 2006 Part 1: Photochemistry and photobiologyJOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 3 2007PG Calzavara-Pinton Abstract Photodynamic therapy (PDT) is a two-step therapeutic technique in which the topical or systemic delivery of photosensitizing drugs is followed by irradiation with visible light. Activated photosensitizers transfer energy to molecular oxygen, generating reactive oxygen species (ROS). The subsequent oxidation of lipids, amino acids and proteins induces cell necrosis and apoptosis. In addition, ROS indirectly stimulate the transcription and release of inflammatory mediators. The photosensitizers are selective, in that they penetrate and accumulate in tumour cells or in the endothelium of newly formed vessels while generally avoiding the surrounding healthy tissue. The mechanisms of penetration through the cell membrane and the pattern of subcellular localization strongly influence the type of cellular effect. The photobiology and photoimmunology of the haematoporphyrin (Hp) derivative and its purified, lyophilized and concentrated form porfimer sodium have been investigated over the past 30 years. However, interest in PDT in dermatology was not raised until the 1990s with the availability of a simple and effective technique, the topical application of aminolaevulinic acid (ALA) and its methyl ester (methyl aminolaevulinate, MAL) followed by irradiation with broadband red light. At the same time, several new ,second-generation' synthetic sensitizers (e.g. benzoporphyrin derivatives, phthalocyanines, chlorins and porphycenes) became available. These compounds are chemically pure, highly efficient, selective and safe, while offering the advantage that the generalized skin photosensitivity they produce lasts for only a short time. They are currently under clinical evaluation but have not yet been approved for clinical use. This paper provides an overview of the chemistry of the photosensitizers, the photobiology and photoimmunology of the photodynamic reaction as well as the photophysical characteristics of the light sources available for PDT. [source] Silent mysteries: epigenetic paradigms could hold the key to conquering the epidemic of allergy and immune diseaseALLERGY, Issue 1 2010D. J. Martino Abstract Epigenetic mechanisms provide new insights into how environmental changes may mediate the increasing propensity for complex immune diseases such as allergic disease. There is now strong evidence that early environmental exposures play a key role in activating or silencing genes by altering DNA and histone methylation, histone acetylation and chromatin structure. These modifications determine the degree of DNA compaction and accessibility for gene transcription, altering gene expression, phenotype and disease susceptibility. While there is already evidence that a number of early environmental exposures are associated with an increased risk of allergic disease, several new studies indicate in utero microbial and dietary exposures can modify gene expression and allergic disease propensity through epigenetic modification. This review explores the evidence that immune development is under clear epigenetic regulation, including the pattern of T helper (Th)1 and Th2 cell differentiation, regulatory T cell differentiation, and more recently, Th17 development. It also considers the mechanisms of epigenetic regulation and early immune defects in allergy prone neonates. The inherent plasticity conferred by epigenetic mechanisms clearly also provides opportunities for environmental strategies that can re-programme gene expression for disease prevention. Identifying genes that are differentially silenced or activated in relation to subsequent disease will not only assist in identifying causal pathways, but may also help identify the contributing environmental factors. [source] Five years of progress in the Standardization of Proteomics Data 4th Annual Spring Workshop of the HUPO-Proteomics Standards Initiative April 23,25, 2007 Ecole Nationale Supérieure (ENS), Lyon, FrancePROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 19 2007Sandra Orchard Abstract Over the last five years, the Human Proteome Organisation Proteomics Standards Initiative (HUPO PSI) has produced and released community-accepted XML interchange formats in the fields of mass spectrometry, molecular interactions and gel electrophoresis, have led the field in the discussion of the minimum information with which such data should be annotated and are now in the process of publishing much of this information. At this 4th Spring workshop, the emphasis was on consolidating this effort, refining and improving the existing models and in pushing these forward to align with more broadly encompassing efforts such as FuGE (Jones, A.R., Pizarro, A., Spellman, P., Miller, M., FuGE Working Group FuGE: Functional Genomics Experiment Object Model. OMICS 2006, 10, 179-184) and the Ontology for Biomedical Investigation (OBI). The effort to merge the existing mass spectrometry XML interchange formats, mzData and mzXML, into one single standard mzML yielded significant progress. Also the preliminary design of AnalysisXML was extended to include several new use cases and better support for quantification information. Finally the Molecular Interaction group discussed the development of a molecular interaction scoring system with accompanying gold standard data test sets. [source] Morphological Descriptions of New and Little-Known Benthic Ciliates from Ganghwa Tidal Flat, KoreaTHE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 3 2007JUN GONG ABSTRACT. Ciliates are highly diverse in the benthos where there are rare species to be unrevealed and described. By isolating species during successive and diversified cultivations, we discovered several new and interesting taxa from the top layer sediment of a muddy site in the Ganghwa tidal flat. These include three new species Spirodysteria ganghwaensis n. sp., Uronemella parafilificum n. sp., Zosterodasys minuta n. sp., and one poorly known form Loxophyllum chaetonotumBorror 1965. The morphology of live cells and infraciliature of these four species are described based on living observations, protargol impregnations, and morphometrics. Diagnoses and improved definitions are also provided. The newly established genus Spirodysteria n. g. differs from Dysteria mainly in its spirally twisted body shape. Spirodysteria kahli (Tucolesco 1962) n. comb. (formerly Dysteria kahliTucolesco 1962) has been included in this new genus. [source] Synthesis of New 2,3-Dihydroquinazolin-4(1H)-one Derivatives for Analgesic and Anti-inflammatory EvaluationARCHIV DER PHARMAZIE, Issue 5 2010Osama I. El-Sabbagh Abstract Starting from isatoic anhydrides, several new 2,3-dihydroquinazolin-4(1H)-one derivatives bearing chalcone or pyrazole or thiazole moieties at the third position were synthesized. The analgesic and anti-inflammatory activities for most compounds were studied at a dose level of 50 mg/kg via the acetic-acid-induced writhing-response method and carrageenan-induced edema method, respectively. The study showed that the chalcones bearing a 4-chlorophenyl group 4c or 4-nitrophenyl group 4b were the most active ones as analgesics. Both chalcone 4c and N -phenyl pyrazole bearing 4-methoxy phenyl group 5b showed a higher anti-inflammatory activity than celecoxib but still lower than that of diclofenac sodium. Moreover, the chalcone 4c has nearly the same ulcerogenic index as the selective cyclooxygenase-2 inhibitor celecoxib. [source] Synthesis and Antimicrobial Activity of Some Novel 2-[4-(Substituted Piperazin-/Piperidin-1-ylcarbonyl)phenyl]-1H -benzimidazole DerivativesARCHIV DER PHARMAZIE, Issue 1 2009Canan Kus Abstract In this study, we report the synthesis and antimicrobial evaluation of several new 4-(1H -benzimidazol-2-yl)benzamides (11,30) and 5-chloro-1-(p -fluorobenzyl)-2-{4-[(4-methylpiperazin-1-yl)carbonyl]phenyl}-1H -benzimidazole (33). Compound 20 exhibited the best antibacterial activity with MIC value of 6.25 ,g/mL against Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA). Significant antifungal activities were obtained with the compounds 13, 14, 18, 19, and 33 with MIC values of 3.12 ,g/mL which are close to fluconazole. [source] Dodging matrix effects in liquid chromatography tandem mass spectrometric assays,compilation of key learnings and perspectivesBIOMEDICAL CHROMATOGRAPHY, Issue 5 2009Nuggehally R. Srinivas Abstract Triple quad liquid chromatography mass spectrometric assays (LC/MS/MS) have revolutionized the analysis of drug(s)/metabolite(s) with exceptional speed, sensitivity and selectivity features. From inception to date, several new and innovative features have been regularly proposed by researchers to further enhance the value in the applicability of this analytical tool. However, owing to such compressed run times and scanty sample preparation procedures, LC/MS/MS assays that are not fully optimized generally have issues of matrix effects, where ionization potential is either suppressed or enhanced due to the presence of other materials (endogenous/exogenous) in the matrix. By definition, even co-medications, isomeric or isobaric impurities, and drug excipients used in dosing solutions could also potentially contribute to matrix effects. This article captures some of the interesting work carried out by researchers to understand and handle matrix effects. Additionally, it provides perspectives to effectively deal with matrix effects. Copyright © 2008 John Wiley & Sons, Ltd. [source] | ||||||||||||||||